The present invention relates to data storage, and more particularly, this invention relates to systems and methods for efficiently handling errors.
In customer environments with tape libraries or other access to cartridges written by a population of drives, a given cartridge may contain data written by more than one drive. Reading data written by another drive is known as read interchange. Read interchange can be problematic due to the write characteristics of another drive combined with media type and other factors. This can lead to an increase in error recovery (or error burst) in areas where interchange data is present.
Error bursts, which may include a large number of errors in a given time frame or in a given length of tape, are not easily identified since no permanent errors occur and data continues to transfer across the host/drive interface. Even if individual recovery is only transitory in nature, when it persists over long stretches of tape these error bursts can lead to host command timeouts and excessive processing times that seriously degrade performance. These bursts are often directional in nature, with reported cases of single wrap processing time in excess of 2 hours.
Error detection and control is important to any system in which data passes from one point to another. Error detection and control is particularly important in the data storage industries, as users rely on the integrity of the stored data for everything from day to day operation to long term archiving.
There is therefore a need for effective and efficient ways for reducing the occurrence of error bursts.